diff --git a/auth/auth.py b/auth/auth.py
index 61c6b9a2c..b8d9065e6 100644
--- a/auth/auth.py
+++ b/auth/auth.py
@@ -15,7 +15,7 @@ from data import model
 from data.model import oauth
 from app import app, authentication
 from permissions import QuayDeferredPermissionUser
-from auth_context import (set_authenticated_user, set_validated_token,
+from auth_context import (set_authenticated_user, set_validated_token, set_grant_user_context,
                           set_authenticated_user_deferred, set_validated_oauth_token)
 from util.http import abort
 
@@ -131,10 +131,11 @@ def _process_basic_auth(auth):
   logger.debug('Basic auth present but could not be validated.')
 
 
-def generate_signed_token(grants):
+def generate_signed_token(grants, user_context):
   ser = SecureCookieSessionInterface().get_signing_serializer(app)
   data_to_sign = {
     'grants': grants,
+    'user_context': user_context,
   }
 
   encrypted = ser.dumps(data_to_sign)
@@ -164,6 +165,7 @@ def _process_signed_grant(auth):
   logger.debug('Successfully validated signed grant with data: %s', token_data)
 
   loaded_identity = Identity(None, 'signed_grant')
+  set_grant_user_context(token_data['user_context'])
   loaded_identity.provides.update(token_data['grants'])
   identity_changed.send(app, identity=loaded_identity)
 
diff --git a/auth/auth_context.py b/auth/auth_context.py
index cfc6c7b5d..d4ae381be 100644
--- a/auth/auth_context.py
+++ b/auth/auth_context.py
@@ -30,6 +30,15 @@ def set_authenticated_user(user_or_robot):
   ctx.authenticated_user = user_or_robot
 
 
+def get_grant_user_context():
+  return getattr(_request_ctx_stack.top, 'grant_user_context', None)
+
+
+def set_grant_user_context(username_or_robotname):
+  ctx = _request_ctx_stack.top
+  ctx.grant_user_context = username_or_robotname
+
+
 def set_authenticated_user_deferred(user_or_robot_db_uuid):
   logger.debug('Deferring loading of authenticated user object with uuid: %s', user_or_robot_db_uuid)
   ctx = _request_ctx_stack.top
diff --git a/endpoints/index.py b/endpoints/index.py
index a20c492d6..ca4b73362 100644
--- a/endpoints/index.py
+++ b/endpoints/index.py
@@ -60,7 +60,8 @@ def generate_headers(scope=GrantType.READ_REPOSITORY):
 
         if permission.can():
           # Generate a signed grant which expires here
-          signature = generate_signed_token(grants)
+          user_context = get_authenticated_user() and get_authenticated_user().username
+          signature = generate_signed_token(grants, user_context)
           response.headers['WWW-Authenticate'] = signature
           response.headers['X-Docker-Token'] = signature
         else:
diff --git a/endpoints/registry.py b/endpoints/registry.py
index 07a33c4d9..73610910e 100644
--- a/endpoints/registry.py
+++ b/endpoints/registry.py
@@ -9,7 +9,7 @@ from time import time
 
 from app import storage as store, image_diff_queue, app
 from auth.auth import process_auth, extract_namespace_repo_from_session
-from auth.auth_context import get_authenticated_user
+from auth.auth_context import get_authenticated_user, get_grant_user_context
 from util import checksums, changes
 from util.http import abort, exact_abort
 from auth.permissions import (ReadRepositoryPermission,
@@ -463,8 +463,9 @@ def put_image_json(namespace, repository, image_id):
 
   repo_image = model.get_repo_image_extended(namespace, repository, image_id)
   if not repo_image:
-    logger.debug('Image not found, creating image')
-    username = get_authenticated_user() and get_authenticated_user().username
+    username = (get_authenticated_user() and get_authenticated_user().username or
+                get_grant_user_context())
+    logger.debug('Image not found, creating image with initiating user context: %s', username)
     repo_image = model.find_create_or_link_image(image_id, repo, username, {},
                                                  store.preferred_locations[0])